Gas mixtures containing high-value components are used in diverse applications such as the fabrication of semiconductor integrated circuits, liquid crystal panels, solar batteries, solar panels, and magnetic disks, and in the manufacture of aerospace equipment and lighting components. High-value gaseous components also are used in various applications in the medical field. The use of these high-value components may generate effluent or waste gases containing the high-value components and in some cases byproduct components, and these components are often present at relatively low concentrations in gas streams that typically comprise inert gases.
Because of the high cost of these components, and also due to the toxicity of some of these components, it is desirable to recover the components for disposal or reuse. Examples of high-value components include, for example, inert noble gases such as xenon, krypton, argon, and helium, and reactive components such as arsine, hydrogen, deuterium, phosphine, germane, SF6, HF, NF3, CF4, C2F6, and C3F8.
Adsorption processes are well-known for the separation and recovery of such components from process gas effluents or waste gas mixtures. Representative adsorption processes for this purpose are disclosed, for example, in U.S. Pat. Nos. 6,605,134, 7,258,725, 7,261,763, and 7,285,154.
The economic incentive to recover these high-value components is significant; strict environmental regulations on the discharge of toxic high-value components are expected to continue. There is a need in the art for improved adsorption-based processes to recover and reuse these high-value components in a wide range of applications. This need is addressed by the aspects of the invention described below and defined by the claims that follow.